Most good stories start with a fundamental list of ingredients: the initial situation, conflict, complication, climax, suspense, denouement, and conclusion. Great writers sometimes shake up the recipe and add some spice.
Exposition
Ravens, Magicians, and Demons—Oh My
Nick and Alan Ryves are being hunted by magicians who have the ability to summon and control demons. The magicians want something from Nick and Alan, but Nick and Alan aren't giving it up. Instead they just keep moving from town to town trying to stay under the radar… and once they find themselves on the radar? They move again. This is a great set-up for the story, because once we learn this bit of information about the Ryves boys, we know we're in for an interesting ride.
Rising Action
The More the Merrier
Two more teens, Mae and Jamie (who are sister and brother), arrive on the scene and we find out that they, too, have demon trouble. Jamie's been marked by one and someone suggested that the Ryves brothers might be able to help them out—Nick doesn't want to help, but Alan does. Then Alan gets marked by a demon too, and suddenly they're all in this together. The four teens (along with Nick and Alan's dysfunctional mother, Olivia) head off to London in an attempt to capture a few magicians and get both Alan and Jamie's marks removed so they won't become possessed by demons and die slow, painful deaths. So we've got a race against time that's a matter of life and death. How's that for a conflict?
Climax
In the Magician's Lair
After much plotting and planning (and lusting and arguing), the teens make their way into a house where they know the magicians have set up camp… and they all get caught. While being held captive by the magicians, who are being led by their head honcho, Black Arthur, Nick learns many things he didn't know about his life, the most significant item being that he's not human. He's a demon. And that means that if he were freed from his human body, he'd have the power to destroy lots and lots of people and things, and that's why it's particularly climactic when Alan does just that: he sets Nick free, and Nick obliterates Black Arthur before exiting his human body and flying off into the night.
Falling Action
A Bird's Eye View of London
Nick zooms around London in his ethereal demonic form, which seems a lot like a big ball of energy. He soars over buildings and buzzes Tower Bridge, and he feels free, powerful, safe… and homesick. After sixteen years in a human body, he seems to have forgotten how to live as a demon, and more importantly, he misses his brother and wants to make sure Alan is okay. He goes back to the magician's lair and arrives just in time to see the last of the magicians making a run for it. Olivia's dead, and Black Arthur and several other magicians are dead, but Mae and Jamie and Alan are all fine.
Resolution
If the Skin Fits…
Demon Nick squeezes himself back into his human body and pledges never to leave his brother again. Alan embraces Nick, and Nick starts to think that maybe he can get used to being in a body again. There are a few threads left untied, but we're sure those will be tackled in the sequels. Still, this is definitely the denouement because we finally see Nick coming to terms with who he is (more or less), which is something he's struggled with throughout the story.